(1) Field of the Invention
This invention relates to a core for a rolled label strip. More particularly, the invention relates to the improvement in a core for winding a label strip thereon, which core is attached to the core supporting device of a label printing and applying machine or the like.
(2) Description of the Prior Art
The tape-like label strip generally comprises a tape-like label being applied with adhesive on its rear side and a tape-like backing strip, which are longitudinally joined together in layers, and only the tape-like label on the backing strip is cut into small pieces of label units. This tape-like label strip is wound round a cylindrical core. The core carrying the label strip is generally attached to a supporting device which is formed inside the machine frame or on the extension of machine frame of a label printing and applying machine.
By continually operating the label printing and applying machine, the attached tape-like label strip is moved forth in the machine from the supporting device, and the printing, peeling and applying of the label units are repeated one by one. When the rolled label strip on the core is used up, the core is detached from the supporting device and the core of a new rolled label strip is attached to the supporting device of the label printing and applying machine to use it again.
The typical core in the conventional art is generally cylindrical and provided with a circular attaching section on one side of the core. The inner diameter of the attaching section is made smaller than that of the inner wall surface of the cylindrical body. On the periphery of one end face are formed a plurality of raised end faces and arcuate recesses in adjoining relation. On the other end face of the cylindrical body, a plurality of recesses are formed.
In the conventional supporting device for supporting the above core of a label strip, a core supporting member is rotatably fitted to an arm plate that is formed on a label printing and applying machine. The inside surface of the core supporting member is provided with a plurality of resilient tabs arranged in a circle. Each resilient tab is provided with a ridge-shaped engaging projection on its outside. The inner circular edge of the attaching section of the core is fitted to the resilient tabs of the supporting device and the core is then pushed forth so as to be attached. With this operation, the inner surface of the attaching section of the core ride over the engaging projections of the resilient tabs and the tabs are bent inward. After this action, the resilient tabs restore their original postures by their own elasticity, and therefore, the core can be caught by the supporting device.
The above-described conventional core and supporting device, however, have several disadvantages as follows:
(a) The resilient tabs of the supporting device are so small that the flexible ranges of the tabs are very narrow. Therefore, strong force must be exerted on the core to attach it to the supporting device.
(b) When the core is removed from the tabs after the label strip on the core is used up, the core must be forcibly pulled with twisting, so that the tabs are often damaged. In addition, such operation gives the worker uneasy and unpleasant feeling.
(c) When the attaching and detaching of cores are repeated in the use of a label printing and applying machine for a long period of time, the elasticity of tabs is deteriorated and the core supporting force becomes weak, so that the supported rolled label strip often slips off during the use of the machine.
(d) In order to facilitate the attaching and detaching of cores, the surfaces of engaging projections of the tabs must be made smooth, however, from this viewpoint, the core of rolled label strip becomes liable to slip off from the supporting device.